Government Mandates GLOF Reviews for Dams, Ensures Spillway Capacity for Extreme Floods

The government announced mandatory reviews of existing and planned dams vulnerable to Glacial Lake Outburst Floods (GLOFs) to ensure adequate spillway capacity. This initiative, following the collapse of the Teesta-III Hydroelectric dam, aims to enhance disaster preparedness. Studies and monitoring efforts across Himalayan regions are ongoing to manage risks.

The government on Thursday announced mandatory reviews of all existing and under-construction dams at risk of Glacial Lake Outburst Floods (GLOFs) to ensure they have adequate spillway capacity to handle extreme flood scenarios.

A Glacial Lake Outburst Flood (GLOF) occurs due to the failure of a dam containing a glacial lake. Such reviews and GLOF studies have now become mandatory for new dams in glacial lake areas.

Minister of State for Jal Shakti Raj Bhushan Choudhary, in a Lok Sabha response, mentioned that the Central Water Commission (CWC) monitors 902 glacial lakes and water bodies across the Himalayan region annually from June to October.

Following the collapse of the Teesta-III Hydroelectric dam in October 2023, the CWC decided to review all existing and under-construction dams' spillway capacities to handle Probable Maximum Flood/Standard Probable Flood scenarios and GLOFs.

This initiative helps detect changes in water spread areas, focusing on lakes that have significantly expanded and pose disaster risks. The CWC's monthly monitoring reports, accessible publicly, provide transparency and updates on glacial lake conditions.

The Ministry of Power identified 47 dams, including 38 commissioned and 9 under construction, potentially affected by GLOFs. GLOF studies on 31 projects have been completed.

The Ministry of Earth Sciences and the National Centre of Polar and Ocean Research (NCPOR) have been observing two pro-glacial lakes in the Chandra Basin since 2013, aiding scientific research in the area.

The National Institute of Hydrology, Roorkee, under the National Mission on Himalayan Studies (NMHS), has developed a comprehensive status report on the impact of climate change on glacial lakes in the Sikkim Himalayas.

Additionally, the Central Pollution Control Board (CPCB) identified 3,526 grossly polluting industries in the Ganga Basin. Of these, 2,855 are operational, with 671 voluntarily shut down. Show-cause notices or closure directives were issued to 121 non-compliant industries.

(With inputs from agencies.)